regarding flexibility

There is a lot being written electricity storage these days, and capacity markets, and the integration of variable renewable energy resources. Most of the material originates with lawyers, philosophers, sales people, consultants, politicians and other economists. I invite you to listen to a professional engineer and system operator, very carefully, for 10 minutes.

The system operator is Leonard Kula P. Eng.,Vice-President, Market & System Operations and Chief Operating Officer of Ontario's IESO. If low greenhouse gas emissions are a genuine goal, the messages are pertinent far beyond Ontario. Over the first 7 months of 2017 the IESO shows ~2.8 terawatt-hours (TWh) generated by natural gas-fueled suppliers, which is only about 3.5% of all generation. The output from gas is down over 60% from the same period in 2016, which should push the greenhouse gas intensity of IESO grid generation down to around 15 kilograms CO2e per megawatt-hour - superb for grids that aren't entirely in jurisdictions blessed with plentiful hydro-electric generation sites. From a low emissions standpoint Ontario's system operator might be considered THE system operator.

Lower gas use is one characteristic of Ontario's electricity system of late.

A less positive characteristic is rising curtailment of contracted supply - notably from wind.

While most curtailment looks to be due to surplus generation, either globally or in particular regions of the grid, there is another operational aspect of curtailment closely linked to the decline in gas generation.

Earlier this year I ended a post, Can Wind and Solar be significant contributors to a low emission electricity system, with:

...many commentators...have been skeptical about the ability to operate the grid with little of the gas generation (and previously coal) online, and ready for ramping. I believe Ontario's actual operators of the system - the ones who do it on a daily basis - have a story to tell. That story would likely include improved forecasting, revised wind turbine (and perhaps solar panel) regulation to provide a programmed reactive power element, and rationalized market bid rules forcing the curtailment of wind and solar output prior to impacting nuclear units.
It is variable renewable energy systems that need to be flexible.

Kula indicates the way to make variable renewable energy systems flexible is by curtailing their output.

We added the ability to dispatch the variable generation facilities that are connected to the grid in 2013, and they are very fast acting resources. At times we have to reduce the output of these facilities to go ahead and manage congestions and/or surplus conditions, and once they dispatched down they are very quick and flexible to be dispatched back up.

The IESO's Kula spoke at the 2017 Stakeholder Summit. The IESO requires you register before viewing the recordings (it's a painless process). The section I am addressing is the panel on "Building Flexibility into the Electricity System". While I highly recommend the 10 minutes at the start of the panel in which Kula delivers his presentation , Rob Coulbeck is also worth listening to, as is the Q & A session.

Can Wind and Solar be significant contributors to a low emission electricity system?

...there is a substantial body of evidence that variable renewable integration costs are hugely dependent on the flexibility of the system to which they are being added.

So claims a new report from a UK Energy Research Centre, which lists many studies after opining on them in The costs and impacts of intermittency – 2016 update. Integration costs are important and I'll write on some of the content of the UK paper in paragraphs below, but first I want to discuss the bias of the work, and a great accomplishment in Ontario.

Taken together, the full range of impacts add weight to the message that electricity systems and markets need to adapt and be reorganised to incorporate large proportions of variable renewable generation most efficiently. 

systems and markets may not be what "need" to adapt.

The key challenge facing policymakers, regulators and markets is how to ensure delivery of a flexible, low carbon system that makes maximum use of variable renewable generation whilst minimising overall cost and enhancing security and reliability. 

It is wrong to state a low carbon system maximizes "use of variable renewable generation."

My estimates indicate in January - usually one of the highest demand months of a year - Ontario generated less electricity with fossil fuels than in any month since at least 1973. Probably the least of any month in my life (I was born the day Dylan shocked Newport with an electric performance).

Loss and legacy: the week that was

Sad news this past week as David MacKay died.
Mark Lynas provided a moving tribute in What David MacKay taught me, and taught us all

David MacKay had more personal and professional integrity than anyone I have ever known – and yet somehow he managed to combine it with a warmth that underlay everything he did. (I was privileged to attend his celebratory Symposium in Cambridge just a month ago – I don’t think I have ever been in a scientific meeting with so much love in the room.) He wore his super-intelligence – people use the word ‘genius’ rarely these days, but I’ve heard it used for David a number of times – lightly, and always interacted with humility and an enduring sense of fun.
David had a strong moral compass and sense of justice – his work was fundamentally driven by a desire to make a difference, and to help solve real problems, even intractably huge problems like climate change. His massive contribution was bring numeracy to a debate obscured by mudslinging and ideologically-motivated rhetoric (both of which I’m as guilty of as anyone). It was characteristic of this desire to see real change that he accepted the immense challenge of taking on the role of Chief Scientific Advisor at the UK government’s Department of Energy and Climate Change, rather than staying in the ‘ivory tower’ of Cambridge, after the enormous success of his epochal book Sustainable Energy, without the hot air."

The 2050 Energy Calculator continues to have a home a the U.K. Department of Energy and Climate Change, where MacKay first developed it, and calculators have been replicated for many countries around the world.

It took me a while to get to Managing Flexibility Whilst Decarbonising the [Great Britain] Electricity System. It's as good a segue into other recent items I can come up with. (page, full report, slide deck). I want to hit a couple of points here that may alienate newcomers to the topic of generation supply mixes and emissions, so best I quote the background provided by the report's writers:

Germany's electricity market policy this week: A pure energy market with a safety net

There are 2 aspects of German energy policy that are clearly desired:

1. they wish "renewables" - which for the sake of this post are better called by Rod Adams' term "unreliables"
2. they don't want to subsidize fossil fuel generating stations

The two desires probably aren't compatible if one defines paying for capacity as a subsidy, which seems to have been the government's position since prior to the last election when then Minister Altmaeir stated; "I am against blanket subsidies for fossil energy, which would only increase power prices."

I'll review some recent news of how Germany's attempt to structure a market that could allow sufficient capacity at all, or maybe just most, times

New power market design without capacity mechanism in ministry plans | Clean Energy Wire

The German energy ministry has opted for a reformed energy only market (EOM), in which back-up power stations are financed through sharp peaks in power prices. Utilities insisted that a decision on the market's design - either an energy only market or their preference, a capacity market - was still open, saying they needed to be paid for keeping capacity available in the absence of power from renewable sources.
The government has rejected the idea of financial support for fossil-fuel power plants to back up fluctuating power from renewables, a leaked document agreed by the energy ministry and Angela Merkel's chancellery shows. In the paper seen by the Clean Energy Wire, the government argued it was convinced its plan without a capacity market would "guarantee a high level of supply security at low cost."
Reforming the power market is one of the next big steps in the country’s transition to a low-carbon economy, the so-called Energiewende...

continue reading at Clean Energy Wire.

The article notes that in an Energy Only Market. "Supply for peak demand should be secured by letting investors in back-up power stations make very high profits in times of scarcity." I'll opine this is a theoretical belief (I suspect the odd rolling blackout would be preferred), but it is the theory, and the place it's most pursued is probably Texas, where the maximum market price is being raised towards $10000/megawatt-hour.

Handelsblatt has a subscriber-only article on the topic titled, Gabriel Pulls Plug on Utility Bailout.

So the first storyline is that there will be no capacity market - because paying for capacity would just be propping up old utilities and their fossil fuel generating stations.

The other storyline is that Germany will be putting out calls for capacity

would you could you with a tree? energiewende con'd

Reporters on the status of Germany's energy transition have been presenting some optimistic figures recently.
Renewables Internationale was one outlet noting figures for the first nine months of 2013, produced by Fraunhofer ISE, indicating "non-hydro renewables the number one power source in Germany for the first time."

Graphic from Fraunhofer ISE (page 6)

The groupings required to make that statement are interesting: renewables include the infrequently discussed "Biomass" without which the "non-hydro" renewables would not beat either lignite of coal - or uranium/nuclear.

Not only is generation from "biomass"the highest of the renewables for the first three quarters of 2014, it also has the most growth over the same period in 2013.  Biomass outgrowing wind is nothing new in Germany; between 2002 (when the nuclear phase-out first became policy) and 2013, generation from wind turbines more than tripled while the growth rate in generation from biomass almost tripled the growth  rate in wind (increasing over 900%). source - AGEB